From: Frédéric Pétrot <[email protected]>
Lq shares the cmo opcode space, but the cbos must have rd = 0.
Now ensure that they are matched only in that case.
This implies that lq can be recognized as such only when rd != 0.
Update the decoder file accordingly.
Fixes: 9273cda722 ("disas/riscv.c: add 'cbo' insns to disassembler")
Reported-by: Julien Thillard <[email protected]>
Signed-off-by: Frédéric Pétrot <[email protected]>
Reviewed-by: Daniel Henrique Barboza <[email protected]>
---
disas/riscv.c | 20 +++++++++++---------
target/riscv/insn32.decode | 2 ++
2 files changed, 13 insertions(+), 9 deletions(-)
diff --git a/disas/riscv.c b/disas/riscv.c
index b8099cbdf8..e85dbac035 100644
--- a/disas/riscv.c
+++ b/disas/riscv.c
@@ -1281,22 +1281,24 @@ static const rv_opcode_data
*decode_inst_opcode(rv_decode *dec, rv_isa isa)
case 2:
/*
* 'lq' shares the "(...) 010 ..... 0001111" opcode space
- * with 'cbo' insns. Check the next 5 bits to select
- * what we want:
+ * with 'cbo' insns.
*
* cbo_inval 0000000 00000 ..... 010 00000 0001111
* cbo_clean 0000000 00001 ..... 010 00000 0001111
* cbo_flush 0000000 00010 ..... 010 00000 0001111
* cbo_zero 0000000 00100 ..... 010 00000 0001111
*
- * Anything that doesn't match these will default to 'lq'.
+ * lq matches when rd != 0
*/
- switch ((inst >> 17) & 0b11111) {
- case 0: return &op_cbo_inval;
- case 1: return &op_cbo_clean;
- case 2: return &op_cbo_flush;
- case 4: return &op_cbo_zero;
- default: return &op_lq;
+ if ((inst >> 7) & 0b11111) {
+ return &op_lq;
+ } else {
+ switch (inst >> 20) {
+ case 0: return &op_cbo_inval;
+ case 1: return &op_cbo_clean;
+ case 2: return &op_cbo_flush;
+ case 4: return &op_cbo_zero;
+ }
}
}
break;
diff --git a/target/riscv/insn32.decode b/target/riscv/insn32.decode
index 21272fdb50..aa02dae3c9 100644
--- a/target/riscv/insn32.decode
+++ b/target/riscv/insn32.decode
@@ -216,6 +216,8 @@ ldu ............ ..... 111 ..... 0000011 @i
]
# *** RVI128 lq ***
+ # *** Catches an lq with rd = 0, which we disallow
+ illegal ------------ ----- 010 00000 0001111
lq ............ ..... 010 ..... 0001111 @i
}
sq ............ ..... 100 ..... 0100011 @s
--
2.43.0
